Comparison study of ammonium ions adsorption on zeolite activated carbon and amino functionalized silica in aqueous solutions

THAI NGUYEN UNIVERSITY OF AGRICULTURE AND FORESTRY NATIONAL CHIAO TUNG UNIVERSITY NGUYEN DUC MANH COMPARISON STUDY OF AMMONIUM IONS ADSORPTION ON ZEOLITE, ACTIVATED CARBON AND AMINO-FUNCTIONALIZED SILICA IN AQUEOUS SOLUTIONS BACHELOR THESIS Study Mode Major Faculty Batch : Full-time : Environmental Science and Management : International Programs Office : 2013 - 2017 Thai Nguyen, 2017 Thai Nguyen University of Agriculture and Forestry Degree Program Bachelor of Environmental Science and Management Student name Nguyen Duc Manh Student ID DTN1354110099 Thesis Title Comparison Study of Ammonium ions Adsorption on Zeolite, Activated carbon and Amino-functionalized silica in aqueous solutions Supervisor(s) Prof Sue-Min Chang Assoc Prof Nguyen Thi Ha Supervisor’signature Abstract: This study examined the capability of Amino-functionalized silica, Activated carbon and Zeolite, to remove ammonium ions from water Studies were conducted to examine the ammonium removal capacity of these three materials under various experimental conditions of contact time and ammonium concentration The adsorption materials were prepared and investigated by various techniques including Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) to examine the functional groups and surface areas, respectively The pseudo firstorder, pseudo second-order kinetic models were used to describe the kinetic data The ammonium removal data for Amino functionalized silica and Activated carbon most highly correlated with pseudo-first-order adsorption reaction model, whereas Zeolite was best fitted with pseudo-second-order model The Langmuir and Freundlich models were applied to describe the equilibrium isotherms for ammonium adsorption capaciy The findings showed that the adsorption of ammonium on the Activated carbon was best fitted with the Langmuir model,Zeolite was best fitted with the Freundlich model, Amino functionalized silica could be described by both Langmuir and Freundlich model The results also indicated a significant potential of the Amino functionalized silica as an alternative adsorbent material for ammonium removal from aqueous solutions Keywords Amino groups, Adsorption, Aminofunctionalized material, ammonium ion ( ) Number of pages 47 Date of submission 20/9/2017 ACKNOWLEDGMENT The completion of this thesis would not have been possible without the help of many people At this very moment of accomplishment, I would like to express my sincere gratitude to my supervisor Prof Sue Min Chang, Professor Institute of Environmental Engineering National Chiao Tung University, Taiwan Thanks for giving me the opportunity to be a student of Environmental Nanomaterial Lab, as well as who suggested the topic and support me during the internship time Secondly, I would like to express my sincere gratitude to Assoc Prof Nguyen Thi Ha, Faculty of Environmental Science, VNU University of Science, Ha Noi, Viet Nam Thanks for her guidance, encouragement and support throughout the entire study and complement of this thesis I am thankful to Environmental Nanomaterial Laboratory of National Chiao Tung University for providing me facilities to conduct my research work I am also thankful to all members in the laboratory for their help during my internship course Student guy n c nh ~i~ TABLE OF CONTENTS ACKNOWLEDGMENT i LIST OF FIGURES iv LIST OF TABLES v LIST OF ABBREVIATIONS vi PART : INTRODUCTION 1.1 Research rationale 1.2 Research’s Objective 1.3 Research’s Contents 1.4 Research’s Scope PART : LITERATURE REVIEW 2.1 General introduction to ammonium nitrogen 2.2 Methods for removing ammonium form water 2.3 Basic of adsorption theory 2.4 Introduction of Activated Carbon 10 2.5 Introduction of Zeolite 14 2.6 Introduction of Amino functionalized silica 18 PART : MATERIALS AND METHODOLOGY 20 3.1 Materials 20 3.2 Experimental methods 20 3.2.1 Synthesis Amino-functionalized silica 20 3.2.2 Prepare water sample 21 3.2.3 Investigate the adsorption capacity 21 ~ ii ~ 3.2.4 Investigate the kinetic of ammonium adsorption 21 3.2.5 Investigate the isotherm of ammonium adsorption 22 3.2.6 Analysis Methods 22 PART : RESULTS AND DISCUSSION 24 4.1 Adsorbents characterization 24 4.1.1 BET characterization 24 4.1.2 FTIR spectra 25 4.2 Results of ammonium removal capacity investigation 26 4.2.1 Effect of contact time 26 4.2.2 Effect of ammonium concentration 28 4.3 Results of Kinetic model and Isotherm model investigation 29 4.3.1 Results of Kinetic model investigation 29 4.3.2 Results of Isotherm model investigation 30 PART : CONCLUSION AND RECOMMENDATION 34 5.1 Conclusion 34 5.2 Recommendation for future study 35 REFERENCES 36 ~ iii ~ LIST OF FIGURES Figure.1: Ammonium chemical structure Figure.2: Formation of Ammonium Figure.3: Schematic Representation of (a) graphitizing and (b) non-graphitizing structure of carbon Figure.4: Micropore, Mesopore and Macropore Regions of Activated Carbon Figure.5: Primary structural units of zeolite – tetrahedron ; ; Figure.6: Secondary structure units of the zeolite Figure.7: Synthesis Amino functionalized silica process Figure.8: BET surface area of Amino functionalized silica, Zeolite and Activated carbon Figure.9: FTIR spectra of Amino functionalized silica, Zeolite and Activated carbon Figure.10: Ammonium removal efficiency using Amino functionalized silica, Activated carbon and Zeolite Figure.11: Effect of initial ammonium concentration to equilibrium adsorption Figure.12: Linear plot of Langmuir isotherm of Figure.13: Linear plot of Freundlich isotherm of ion adsorption on three sample ion adsorption on three samples ~ iv ~ LIST OF TABLES Table Ammonium ion adsorption on some adsorbents Table Summarizes basic structural data of some common zeolite Table Kinetic parameters for ammonium removal using the pseudo-first-order model and pseudo-second-order model Table4 Isotherms constants for the ammonium exchange by three sample ~v~ LIST OF ABBREVIATIONS AC : Activated Carbon BET : Brunauer–Emmett–Teller FTIR : Fourier Transform Infrared Analysis : concentration in the solution at equilibrium (mg/L) : Pseudo-first-order adsorption constant : Pseudo-second-order adsorption constant and n: Freundlich constant : Lang-muir constant : Adsorption capacity at equilibrium conditions : Maximum adsorption capacity ( mg/g) : Adsorption capacity at time t : Correlation coefficient value ~ vi ~ PART : INTRODUCTION 1.1 Research rationale Water is one of our most important natural resources However, Due to increased anthropogenic activities and thus increased waste generated which causes environmental pollution, supplying safe drinking water is the highest challenge of communities during the current century(Moussavi et al 2011) For all practical purposes, water pollution is the addition by humans of something to the water that alters its chemical composition, temperature, or microbial composition to such an extent that harm to aquatic life and on those who consume the water (Lioyd,1992) One of the sources that cause water pollution is Nitrogen and its compounds Nitrogen compounds are very essential elements for living organisms However, the presence of excess Nitrogen compounds causes environmental pollution Agriculture activities are associated with use of fertilizers on a large scale, industrial wastewater, domestic wastewater which rich of Nitrogen compound discharged into the environment causing adverse effect to aquatic ecosystems Ammonia and ammonium ions are the more commonly encountered Nitrogen compounds in waste water, these nutrients in aquatic ecosystems cause diverse problems such as imbalance of natural ecological systems and increase of eutrophication, depletion of dissolved oxygen in surface waters which kills fishes and create septic condition, odor problems, increase risks to human health (Carpenter et al 1998) Therefore, the control on them has vital importance for the protection of public health ~1~ PART : RESULTS AND DISCUSSION 4.1 Adsorbents characterization 4.1.1 BET characterization As stated above, three adsorbents were analyzed by using BET measurement machine The data are showed in Figure below: BET 250 215,4 Surface area ( m2/g) 200 SiO2-NH2 150 Zeolite 100 Activated carbon 50 2,55 6,87 Adsorbents Figure BET surface area of Amino functionalized silica, Zeolite and Activated carbon The BET specific surface areas of Amino-functionalized silica, zeolite and activated carbon were reported by chart to be 2.55, 6.87 and 215.4 , respectively The BET values of activated carbon are much more higher than amino functionalized silica and zeolite This could be due to the size of adsorbent (Activated carbon and Zeolite were the particles whereas Amino-functionalized silica was the powders ~ 24 ~ 4.1.2 FTIR spectra The Infrared spectra of the material is measured by Philips XL30 microscope machine in Nano Material Laboratory–Chiaotung university–Taiwan Sample is measured by diffuse reflectance technique, the sample powder was mixed with KBr substrate.The spectrum was obtained over the range of 500-4000 The result are illustrated in Fig.9 below Figure FTIR spectra of Amino functionalized silica, Zeolite and Activated carbon As shown in Fig.9 The FT-IR spectra of the activated carbon, the band at 3429 and 1080 represents the O–H stretching vibrations band that corresponds to the surface hydroxyl groups from carboxyls, phenols, or alcohols (Figueiredo et al 1999) According to Montes-Morán et al the bands observed in the region between 1600 and ~ 25 ~ 1440 represents the aromatic and aliphatic C=C stretching vibrations (Montes- Morán et al 2004) For Amino functionalized silica The broad adsorption peak at about 3,420 and the peak at around 700 was assigned to N-H stretching vibration and bending at 1510 indicating the incorporation of amino group Strong adsorption peaks at about 1,113 were observed for the samples, indicating the existence of Si-O-Si stretching vibration of silanol groups (Li et al 2012) The characteristic band in Zeolite represents hydroxyl group stretching around 3441 , C=O stretching at about 1655 from around 1000 to 500 , and a group of vibration bands ranging representing oxygen bonded with Si or Al in a tetrahedral confirmation (Moussavi et al 2013) 4.2 Results of ammonium removal capacity investigation 4.2.1 Effect of contact time A critical consideration when applying the adsorption system under given condition is to provide a sufficient contact time to reduce the contaminant(s) in a contaminated solution with a known concentration to desired value Hence, it is technically important to investigate the influence of contact time on the removal of ammonium by adsorption onto amino functionalized silica and the selected zeolite and activated carbon The effect of a contact time between and 24 hour was examined on the removal of 50 mg/L concentration of ammonium Fig.10 presents the results of this phase of study in terms of ammonium removal percentages by three adsorbent ~ 26 ~ SiO2-NH2 Ammonium removal (%) Ammonium removal (%) Activated carbon 60 60 50 40 30 20 10 50 40 30 20 10 0 10 20 Contact time (h) 30 10 20 Contact time (h) Fig 10 (a) 30 Fig 10 ( b ) Zeolite Ammonium reoval (%) 60 50 40 30 20 10 0 10 20 Contact time (h) 30 Fig 10 ( c ) Figure 10 Ammonium removal efficiency using Amino functionalized silica (a) Activated carbon (b) and Zeolite (c) Based on data shown in Fig.10 (a), the ammonium - removal efficiency by the Amino functionalized silica rapidly increased to 43% within the first hours Subsequently, by further increasing the contact time, the ammonium removal efficiency correspondingly increased, and sorption equilibrium was established after hours There is a similar trend of adsorption onto zeolite (Fig.10 c) with amino functionalized ~ 27 ~ silica, the ammonium removal reached a high amount (49%) within first hour The rapid removal of ammonium by zeolite can be related to the textural characteristics of zeolite However, for activated carbon, there is a steady increase of ammonium removal in contact time process as well as the absorption process is slow 4.2.2 Effect of ammonium concentration equilibriu adsorption (mg/g) Sio2-nh2 Activated carbon Zeolite 0 20 40 60 80 initial concentration (mg/L) Figure 11 Effect of initial ammonium concentration to equilibrium adsorption Based on data in Fig.11 The results of experiments are presented as a function of the different starting concentrations of initial ion From Fig.11, it seen that as the concentration increased the removal efficiency of ion decreased This may be attributed to the adsorbent tending to become saturated in adsorption on to three adsorbents The adsorption capacity of amino-functionalized silica and zeolite reached equilibrium when concentration of ammonium increase up to 60 mg/L while for activated carbon which is 40 mg/L, its mean the adsorption does not occur anymore, because of the limited numbers of vacancies on the surface of adsorbents ~ 28 ~ Based on data from Fig 11, its showed that the optimal concentration for ammonium adsorption on Amino-functionalized silica and Zeolite were 50 mg/L Whereas for Activated carbon that was only 30 mg/L 4.3 Results of Kinetic model and Isotherm model investigation 4.3.1 Results of Kinetic model investigation To investigate the mechanism involved in the uptake onto Amino functionalized, activated carbon and zeolite, the pseudo-first-order and pseudo-secondorder kinetic model were used for the analysis of ion exchange The pseudo first order equation is expressed as: Ln ( ) = Ln ( ) (3) The pseudo second order equation is expressed as: (4) The result are shown in Table below: Pseudo-first-order model Pseudo-second-order model 0.0024 0.98 0,000054 0.979 Activated carbon 0.0013 0,000041 0.94 Zeolite 0.0071 0.91 0.00027 0.99 Table Kinetic parameters for ammonium removal using the pseudo-first-order model and pseudo-second-order model ~ 29 ~ On comparing the correlation coefficients listed under Table 2, it was found that the ammonium removal on the amino functionalized and activated carbon could be described well by the pseudo-first-order kinetic model, which has a higher correlation coefficient value ( and 1, respectively ) With zeolite, the correlation coefficient value higher for pseudo-second-order, then the mechanism of ammonium adsorption onto zeolite fit with pseudo-second-order model 4.3.2 Results of Isotherm model investigation The adsorption isotherm indicates how the adsorption molecules distribute between the liquid phase and the solid phase when the adsorption process reaches an equilibrium state The analysis of the isotherm data by fitting them to different isotherm models is an important step to find the suitable model that can be used for design purpose There are several isotherm equations available for analyzing experimental adsorption equilibrium data.In this study, the equilibrium experimental data for adsorbed on three sample were analyzed using the Langmuir and Freundlich models The equation of the Langmuir isotherm is as follows: (5) Where (mg/g) and (mg/L) are the amount of zeolite at equilibrium and the respectively; ( mg/g) and adsorbed by per unit mass of concentration in the solution at equilibrium, (L/mg) are the maximum adsorption capacity of ~ 30 ~ three sample and the Lang-muir constant, respectively The linear plot of Langmuir isotherm is shown in Fig 12, It is noted that the values of and were calculated from the slope and the intercept of the plot, respectively, and are given in Table The maximum amount of adsorbed by the amino-functionalized silica, activated carbon and zeolite at equilibrium ( ) were 10.21, 19.03 and 33.2 mg/g, respectively 14 12 Ce/qe ( g/L) 10 SiO2-NH2 Activated carbon Zeolite 0 20 40 Ce ( mg/L) 60 Figure 12 Linear plot of Langmuir isotherm of 80 ion adsorption on three sample Langmuir Freundlich 1/n 0.99 0.83 52.1 6.55 0.98 1.42 0.37 AC 0.96 0.31 21.03 4.8 0.87 0.64 0.34 Zeolite 0.96 0.25 33.2 5.5 0.98 0.38 0.71 Table Isotherms constants for the ammonium exchange by three sample ~ 31 ~ Freundlich 0,90 0,80 0,70 SiO2-NH2 log qe 0,60 Activated carbon 0,50 Zeolite 0,40 0,30 0,20 0,10 0,00 0,00 0,50 1,00 1,50 2,00 log Ce Figure 13 Linear plot of Freundlich isotherm of ion adsorption on three samples The linear form of the Freundlich model is given by the following equation: (6) where (mg/g) is a Freundlich constant indicating the adsorption capacity of absorbent, and 1/n is an empirical parameter related to the intensity of sorption, which varies with the heterogeneity of the material (Marón et al 2006) Freundlich constants can be calculated from the slope and intercept of Fig.13 and the data are given in Table In addition, the 1/n constant for the Freundlich isotherm is a measure of exchange intensity or surface heterogeneity and ranges between and In this study, the values of 1/n for all anion species were less than which suggested that the adsorption conditions were favorable (Raji and Anirudhan 1998) From Table 3, it was found that the ammonium adsorption on Amino- functionalized silica could be fitted with both Langmuir model and Freundlich model ~ 32 ~ becauses of the correlation coefficient value were quite close together = 0.98 respectively Langmuir model yields a much better ( = 0.99 and = 0.96) fit to the Activated carbon data compared with that of the Freundlich model ( = 0.87) For Zeolite, the equilibrium adsorption data was best fitted with Freundlich model ( = 0.98) ~ 33 ~ PART : CONCLUSION AND RECOMMENDATION 5.1 Conclusion In this study, three material were characterized and used for the removal of ammonium form water The following conclusions were based on the results obtained from the experiment:  Amino functionalized silica was powders sized material with particle diameters of 316 nm Zeolite and Activated carbon were granular materials The BET surface area of Amino functionalized silica, zeolite and activated carbon were 2.55, 6.87 and 215.4 /g, respectively  The time for ammonium adsorption to reach equilibrium state on Zeolite, Amino-functionalized silica and Activated carbon were hours, hours, and hours respectively The optimal concentration for ammonium adsorption on Amino-functionalized silica and Zeolite were 50 mg/L, whereas for Activated carbon that was only 30 mg/L  For kinetic model, the experimental time course adsorption data of Amino functionalized silica and Activated carbon most highly correlated with pseudo-first-order model, Zeolite fitted with the pseudo-second-order model  The equilibrium adsorption data of Activated carbon was best fitted with the Langmuir model that mean ammonium adsorption is Single-layer adsorption on adsorption materials Zeolite was best fitted with Freundlich model which indicate ammonium ion adsorption under heterogeneous material surface conditions For Amino functionalized silica, which could be correlated with both Langmuir and Freundlich model ~ 34 ~  Amino functionalized silica attained greater ammonium adsorption efficiency than Zeolite and Activated carbon under similar conditions Ammonium adsorption capacity of Amino functionalized silica were 6.55 mg/g, Zeolite 5.5 mg/g and Activated carbon 4.8 mg/g  Based on the results, it can be concluded that the Amino functionalized silica material is suitable adsorbent for ammonium ion removal from aqueous solution Hence, Amino Functionalized Silica may be used as an alternative material for purifying water due to its potentials 5.2 Recommendation for future study  Investigate the other effects such as pH, temperature, stirring speed, dosage of adsorbent on ammonium removal capacity  Investigate the adsorption capacity of Amino functional silica, Zeolite and Activated carbon for some heavy metal ions  Examine the ability of Amino functionalized silica for wastewater which has higher concentrations of ammonium ~ 35 ~ REFERENCES a) Mousavi, Gholamreza Talebi, Sadegh, Farrokhi, Mehrdad Sobouti, Robabeh 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Investigate the ammonium adsorption capacity of Amino- functionalized silica and compare with Activated carbon, Zeolite and Amino- functionalized silica under different experimental conditions in aqueous. .. silica, Zeolite and Activated carbon Figure.9: FTIR spectra of Amino functionalized silica, Zeolite and Activated carbon Figure.10: Ammonium removal efficiency using Amino functionalized silica, Activated